TEGUCIGALPA, Honduras -- Honduran officials said Friday that archaeologists have begun excavations at a mysterious site on Honduras' Caribbean coast that may be the long-rumoured "White City" ruins.

Officials said excavation that began Wednesday have so far unearthed about five dozen stone and ceramic fragments and other artifacts.

Also known as the "City of the Monkey God," the site is located in Honduras' jungle-covered Mosquito coastal region.

The dig is being carried out by archaeologists from Honduras' Institute of Anthropology and Colorado State University.

Institute Director Virgilio Paredes said the site did not appear to be Mayan, the culture that dominated other sites in the region.

"It is a new culture, or a different culture," Paredes said.

He said that jars and bowls had been discovered that bore decorations that appeared to represent humans, jaguars, buzzards, lizards and birds. The pieces appear to date to between 1,000 and 1,500 AD, Paredes said.

The most striking piece discovered appears to be a ceremonial seat or throne made of stone, carved with the figure of a jaguar.

The city's name is believed to be derived from the white limestone rock in the area, or a cult purported dedicated to a monkey god.

Honduran President Juan Orlando Hernandez visited the site and said in a statement "We are blessed to be alive at such a special time in Honduran history."

"This discovery has created a lot of excitement because of its significance for Honduras and the world," Hernandez said.

Honduras' Minister of Science, Ramon Espinoza, said "there will be further research to gather more data, because there is no other site in central America with a lost civilization."

The area is inhabited by the Pech and Payas indigenous groups, who long spoke of such a site. The first written reference came in 1544, in a document written by Spanish Bishop Cristobal de Pedraza.

U.S. adventurer Theodore Morde claimed to have discovered "The Lost City of the Monkey God" in 1940, but didn't reveal the location.

The rumoured site had supposedly been located and lost between the 1500s and the 1800s. Researchers detected the current excavation site in 2012.